Incandescent electric lamp



(Nd Model.)

A. L. RBINMANN.

INGANDBSOENT ELBQTRIG LAMP. N0. 353,158; Patented'Nov. 23, 1886 WITNESSES: INVENTOR',

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2 UNITED STATES PATENT OFFICE.

ALBERT L. REINMANN, OF PITTSBURG, PENNSYLVANIA.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 353,158, dated November 23, 1886.

Application filed August 12, 1886. Serial No. 210,669. (No model.) F

To ctZZ' whom it may concern.-

Be it known that I, ALBERT L. REINMANN, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new'and useful Improvements in In candescent Electric Lamps, of which improvements the following is a specification.

In the accompanying drawings, which make part of this specification, Figure 1 is a view in side elevation of the filaments and platinum electrodes of an incandescent electric lamp, showing my improved means of securing the filaments in place. Fig. 2 is an end view of the apparatus shown in Fig. 1. Fig. 3 is a detail view of the platinum electrode, having one of its ends flattened preparatory to forming the socket for the filament.

The invention herein relates to certain improvements in the manner of securing carbon filaments of incandescent electric lamps to the platinum electrodes. These filaments are usually secured to the. electrodes by inserting the ends of the filaments in a sooket'formed on one end of each electrode, then cementing the filaments therein by a deposit of carbon. This deposit is usually obtained by placing the filaments and electrodes in a suitable fiuid, and then passing an electric current through the filament and electrodes, thereby causing a deposit of carbon on the filament. In order to localize this deposition of carbon, and thus to preserve the previously-regulated resistance of the filament, it is customary to electrically connect the two legs of thefilament at points closely adjacent to the platinum socket by a bar or rod having higher conducting qualities than the filaments, thereby preventing the electric current from traversing the greater portions of the legs and loop of the filament. This method of procedure is practical and successful when filaments of comparatively large cross-sectional area are used; but when it is desired to make highresistance lamps, thus necessitating the employment of filaments of very small cross-sectional area, and therefore very frail, it is found that the weight of the connecting bar or rod above referred to will either break the filaments or so bend them to one side as to render them useless.

The object of the invention herein is to provide means for the successful cementing of the filaments in place without liability of breaking or bending the same, and without disturbing their previously-regulated resistance; and to this end the invention consists in the method and devices as hereinafter more fully described and claimed.

In carrying out my invention the ends of the platinum electrodes 1 are flattened, as shown in Fig. 3, the flattened ends being then bent to form sockets 2, (see Figs. 1 and 2,) and the electrodes are then secured in a glass support or holder,3. The ends of the fine carbon filament 4 are then inserted in the sockets 2, as are also the carbon rods 5, the filament and rods 5 being lightly clamped by closing the sides of the socket. The rods 5 are considerably larger than the filaments,and are of higher conducting properties, so that they will easily support the connecting-bar 6, and will form a better conductor for the current during the cementing operation above referred to. After the ends of the filament and the carbon rods have been placed in the sockets 2, as above described, the connecting-bar 6 is placed on the carbon rods, and the filament rods,sockets, and connecting-bar are submerged in a suitable bath and the electrodes connected to any suitable electric generator, the current passing through the electrodes, the carbon rods 5, and the connecting-bar 6. After a sufiicient deposit of carbon has been formed around the ends of the filament and carbon rods they are removed from the bath and the rods broken off at points adjacent to the carbon deposit.

It will be noticed that in the abovedescribed operation the filaments are not subjected to any weight or any injurious manipulation.

I claim herein as my invention- 1. The combination of the platinum electrodes, the carbon filament connected to said electrodes, conductingrods arranged alongside of the legs of the filament and connected to the electrodes, and a conductor connecting the conducting-rods, substantially as set forth.

2. The combination of electrodes provided with suitable sockets, the carbon filament haviug its ends inserted in said sockets, conducting-rods arranged alongside of the legs of the filament and inserted in the sockets, and a conductor connect-iug the conductingrods, substantially as set forth.

In testimony whereof I have hereunto set my hand.

DARWIN S. Worloorr, R. H. WHITTLEsEY. 

